What forms when a large high-pressure system lingers over an area for several days

Answer: Air mass.

An air mass is a volume of air defined by its temperature and water vapor content. It forms when a large high-pressure system lingers over an area for several days. Air masses can cover many hundreds of miles, and they tend to adapt to the characteristics of the surface below them.

In a pressure system, air always moves from the high pressure regions to the low pressure regions - striving to achieve equilibrium. However, due to the rotation of the Earth, the displacement of the air does not happen in a straight line, causing the wind to form a spiral. If it goes in and up, there is low pressure, causing cyclones and storms). If it goes out and down, high pressure occurs, being anticyclone.

Thus, a hardening high pressure system causes atmospheric stability and prevents the formation of clouds. Thus, anticyclones are associated with warm, dry and cloudless weather conditions, particularly in the summer, which usually prevails for a few days or even weeks.